Process for forming alcohols



Plume Feb. 1, 1944 zsiasss- .raoosss ron roams atconons Albert s.Richardson, Wyoming, om, and James E. Taylor, Louisville, Ky., Procterand Gamble Co a corporationof Ohio assignors to The m n r, Iv rrda Ohio.

No Drawing. Application May 21, 1943,

Serial No. mass 8 Claims. (c1. zoo-sea) Ourinvention relates to aprocess for forming alcohols by reacting hydrogen with certain metallicsalts of carboxylic acids.

The present application is a continuation-in- .part of ourapplicationsSerial Nos. 380,072 and 380,073, filed February 21, 1941, and ofapplication serial No. 438,852, filed April 13, 1942. The first of thesediscloses a general process for formlhg alcohols and esters byhydrogenating the corresponding carboxylates of certain metals-at hightemperature and pressure, the second discloses a similar processdirected specifically to forming unsaturated alcohols and esters fromcorresponding unsaturated carboxylates of certain metals,

and the third discloses specific and advantageous applications of theprocess to mixtures of cadmium carboxylates and carbonlates of certainother metals.

- Among the carbox'ylates which respond to the process of the abovementioned applications are those of cadmium. When subjected to reaction*with hydrogen under the conditions of our -eral process cadmium soaps,for example, are

converted to alcohols and esters corresponding to the fatty acidradicals of these soaps, with liberation of metallic cadmium and water:

(RCOO)aCd+5Hz- 2RCH:OH+2HaO+Cd or more double carbon bonds, the alcoholand ester products will for the most part also contain these linkages. T1

In the absence of free or combined metals other than cadmium among thereactants, the second r If the B group of the carboxylate'contains oneof "the above reactions predominates, with production mainly of esters,and only relatively small amounts of free alcohol are produced.

The subject matter and claims of the present application are based uponour dlscovery 'that unexpectedly beneficial results are obtained whenmixtures of cadmium carboxylate with carboxylates of one or more of themetals iron, cobalt,

or'nickel are hydrogenated, as compared with the results obtainableunder comparable hydrogenating conditions with carboxylates 01 any oneof these metals alone. This improvement in resultsmanilests itselt in a.higher percentage re.- duction of carboxyl groups to alcohol groups thanthe percentage obtained when cadmium car.- boxylatesialone arehydrogenated; also, as compared with the hydrogenation of carbowlates ofany of the metals iron,cobalt, and ,nickelalone,

it manifests itself either in a higher percentage reduction of carboxylgroups to alcohol groups or j in a greater preservation of double carbonbonds in unsaturated fatty radicals, or' in both of these effectssimultaneously. In other words, hydrogenating mixtures of carb oxylatesof different metals as specifically claimed in the present applicationresults in unexpectedly high yields 40f alcohols and/or alcohols of anunexpectedly high iodine value.

Thus our present process provides an improved means of forming higheralcohols, which may contain unsaturated carbon-carbon linkages if thestarting materials are unsaturated. Such a process, which isnotjdependent upon added metallic or metal oxide catalysts, has greatadvantages over previously described methods of making higher fattyalcohols. The reaction is rapid,

the yields of the desired product are high, and the metals are readilyrecoverable for reuse in making fresh lots of carboiwlates forhydrogenation.

The following examples will illustrate typical small scale applicationsof our process. In each 'of these examples the hydrogenation was carriedout in a reactionvessel consisting of a stainless steel bomb of 300cubic centimeters capacity. The mixed fatty acids present in commercialoleic acid, or "red oil," are for convenience referred to as "oleicacid," and the alcohols resulting from the process are referred to as"oleyl alcohol.

The extent of the reduction of carboxyl groups iscalculated from thesaponification value of the original oleic acid and the saponificationvalue of .the acid washed, water washed, and dried reaction product. Theper cent total alcohol in the acid washed (andwater washed and dried)product is determined either by calculation from the hydroxyl valuedetermined on the unsaponifiable matter in the acid washed product, orby calculation from the acid value, saponification value, and hydroxylvalue of the acid washed product.

In either case the 'per cent total alcohol includesv both free oleylalcohol and oleyl alcohol combined. as ester,-the latter being liberatedwhen the acid washed product is saponified.

Example 1.'Cadmium oleate and iron oleate were separately prepared bytreating solutions of fred oil sodium soaps with solutions of cadmium wenitrate and iron sulfate respectively, and washing and drying .theprecipitated metallic soaps. A mixture of 50 grams of this cadmiumoleate and 50 grams of this iron oleate was placed in the reaction bombat room temperature. air was dis.- placed from this vessel by admittinghydrogen and venting the bomb, and then hydrogen was introduced to buildup the pressure in the bomb to about 2000 pounds per square inch. Thebomb tents were agitated by rocking the bomb while maintaining apressure of 4000 pounds per square inch by adding more hydrogen whennecessary, fortwo hours. The bomb was then allowed to cool to atemperature convenient for handling, excess gas pressure was released,and

the non-gaseous organic contents were removed, boiled with a aqueoussolution of .hydrochloric acid to remove free and combined metal, waterwashed until free from mineral acid, and dried. This acid washed productwas found to have about 71% of the original carboxyl groups reduced, andto contain slightly over 74% of free and combined oleyi alcohol.

Free alcohol wasobtained from the, acid washed material by reactingfatty acids and esters in this material with caustic alkali, ex.-

tracting with ether, and distilling oi! this solvent.

When cadmium oleate alone was similarly hydrogenated, only 'about 53% oithe carboxyl maps were reduced, and the acid washed hydrogenationproduct contained only about 47% total alcohol. a

When iron oleate alone was similarly hydrogenated, about 75% of thecarboxyl groups were reduced, but the acid washed hydrogenation .productwas found to contain almost no alcohol and to consist mostly ofhydrocarbons.

' Emmple 2.A mixture of 90 grams of cadmium oleate and 10 grams ofnickel oleate was subjected to hydrogenation under conditions comparablewith those of Example 1.

The resulting acid washed product was found to have about 90% of theoriginal carboxyl a,seo,eso

' was sealed and heated to about 340' C. The con- Our process asexemplified by the above'specific applications is applicable totreatment of soaps of all fatty acids occurringin natural vegetable,animal, and marine fats and oils. Thus carboxylates of our preferredmetals and of fatty acids derived from coconut oil, tallow,

vegetable oils, fish oils, hydrogenatedoils, etc..-

may be treated to produce the corresponding fatty alcohols. Similarly,our process is applicable to hydrogenation of metallic salts ofcarboxylic acids generally, although we do not claim that it is equallyefllcientas applied to conversion of all such salts to alcohols. It iswell known, of course, that carboxyl-ic acids and their derivativesdiffer in thermal stability and the outstanding merit of our process asapplied to production of the higher alcohols is due in large part to theresistance of the salts of the fatty acids to decomposition by sidereactions under the conditions employed in our process,

It is to be understood that whereas mixtures of carboxylates of cadmiumand of one or more of the other three metals Fe, Co, Ni are the essen- Ithe maintenance of temperatures between about 240' C. and about 400' 0.,pressures inexcess of 2000 pounds per square inch, the provision of someform of agitation to promote intimate congroups reduced, and to containabout 82% free I and combined alcohol having an iodine value above '10.

.When nickel oleate alone was hydrogenated under comparable conditionsonly 20% of the carboxyl groups were reduced and the hydro-' .genationproduct had an iodine value of only 4.

. Example 3.A mixture of 90 grams ofcadmium oleate and 1d grams ofnickel oleate was subjected to hydrogenation under conditions similar tothose of Example 1 except that the time at the elevated reactiontemperature and Pressure was only one hour.

The resulting acid washed and water washed product contained less than1% of free oleic acid, about 80% 6f free'oleyl alcohol, and about 5% ofoleyl alcohol combined as ester. The

iodine value of the product was 75, indicatinl- -tha't about 79% ofthe-Vdouble carbon bonds re'-,

mained unsaturated.

When nickel oleate alone was hydrogenated under similar conditions nosignificant amount of free or combined alcohol was formed.

Example 4.--A mixture of 90 grams of cadnilum oleate and10 grams ofcobalt-oleate was subjected to hydrogenation under conditions comparablewith those of Example 1.

tact between the hydrogen and the reacting salts.

the maintenance of a constant supply of hydrogen. and time under thesereaction. conditions sufflcient for the attainment of substantialcompletion of the reaction.

The relative proportions of the preferred metals inthe carboxylatemixtures subjected to'o'ur.

process may be varied greatly,with the results more advantageousthanthose obtained by using carboxylate's-of the respective individualmetals.

The relative p oportions referred to in the foregoing examples have beenfound to be quite favorable. Having thus described our invention. what-we claim and desire to secure by Letters Patent is: 1. In a process forforming alcohols, the step which consists essentiallyof subjecting toreaction with hydrogen a mixture of salts of carbox'ylic acidscorresponding to said alcohols, said mixture of salts comprisingessentially carboxylates of cadmium and of at least one metal selectedfrom the group consisting of iron, nickel.

and cobalt, the reaction temperature and bydrogen pressurebeing'suiliciently above atmospheric to eifect substantial reduction ofthe car-' boxylicgroup -C0-0- of said ,salts to'the' g-gup-CHs-IO- ofsaid alcohols.

The resulting acid washed product. was found to have about 57% of theoriginal carboxyl srqups reduced and to have an iodine value of 90. Whencobalt oleate alone was hydrogenated under comparable conditions thepercentage re.-

duction of carboxyl groups was even higher,

namely 93%, but the iodine value of the product wasonly.

2. In a process for forming fatty'alcohols. the

step which consists essentially of subjecting to reaction with hydrogena mixture of soaps of fatty acids corresponding to said alcohols, saidmixture of soaps comprising essentially scope of cadmium and of at leastone metal selected from H the group consisting of iron, nickel, andcobalt,

the reaction temperature and hydrogen pressure being sumciently aboveatmospheric to eilect subof said alcohols.

stantial reduction oi the csrboxylic group -COO- of said soaps to thegroup 3. The process of i'orming fatty alcohols, which comprisessubjecting toreaction with hydrogen,,

at atemperature between about 240 and 400 C.'

and at a hydrogen pressure above .2000pounds per square inch,,a mixtureoi scans of fatty acids corresponding to said alcohols, said mixture 0!soaps comprising essentially soaps of cadmium comprise soaps of coconutoil mixed fatty acids.

'l. The process of forming fatty alcohols which comprises subjectingtoreaction with hydrogen, I

sisting of soaps of cadmium and nickel.

8. The process of forming higher alcohols which comprises: subjecting toreaction with hydrogen'. at'a temperature between about 240. and 400 C.and at a hydrogen pressure above 3000. pounds per square inch, a mixtureotscope or fatty acids corresponding to said alcohols, 1 mixture orsoaps comprising essentially soaps or Y cadmium and of at least onemetal selected from the group consisting of iron. nickel and cobalt.removing tree and combined metal from the or-'- ganic reaction productsoi said hydrogenating step by treating with mineral acid; reacting fattyacids and esters in the resulting acid washed I material with causticalkali: and separating lre'e 0 alcohols from the resulting mixture.

ALBERT s. nrcrr'anpsou. JAMES E. rsrnon.

at a between about 240' and (00f 0.; v and at a hydrogen pressure above2000 pounds 1 persquare inch. a mixture or soaps or fatty acids,corresponding-to said alcohols. said mixture con-

